#include <stddef.h>
#include <stdio.h>

char *strchr(const char *str, int ch)
{
	if (str == NULL)
		return (char*)str;

	while (*str && *str != ch)
		++str;
	if (*str == ch)
		return (char*)str;
	return NULL;
}

int main()
{
	printf("0x%p\n", strchr("", 0));
	return 0;
}
